Tool holders and devices for coupling them to machine tool spindles are well known in the art. For example, British patent application No. 2,094,191, published Sep. 15, 1982, shows one such tool holder and coupling device. The coupling device has a socket therein for the accommodation of an extension formed on the tool holder. The extension has a transverse bore slideably accommodating a movable pin. Opposite ends of the pin are engaged by adjustable fastening screws which securely but separably fasten the tool holder to the coupling member. In such construction the coupling member is adapted to be used solely with the one type of tool holder and vice-versa. That is, the coupling member cannot be used with tool holders having coupling means different from that disclosed, and the tool holder cannot be used with coupling devices other than that disclosed. The tool holder and coupling device therein constitute a paired set.
Muendlein et al U.S. Pat. No. 4,976,574 discloses a device for coupling a tool holder to a machine tool spindle similar to that disclosed in the British patent application referred to above. Although the Muendlein et al construction is specifically different from that shown in the British publication, the coupling device again is adapted for use only with the disclosed tool holder and vice-versa.
Other examples of devices for use in coupling a tool holder to a machine tool spindle are shown in Pfalzgraf U.S. Pat. No. 4,877,360 and Dresback U.S. Pat. No. 3,022,084. Again, the coupling devices disclosed in these patents are adapted for use with the specific tool holders disclosed and vice-versa.
Although there are many kinds of tool holders and many kinds of coupling devices, none of the known coupling devices is capable of being used with tool holders having dissimilar coupling means, nor do there appear to be tool holders that can be used with coupling devices having dissimilar coupling means. Accordingly, it appears that the tool holders and coupling devices must be used in paired sets.
A principal object of the invention is to provide interchangeable coupling devices and tool holders so as to permit a particular tool holder to be used with coupling devices having dissimilar coupling means, and vice-versa, thereby avoiding the expense of having to use paired sets of tool holders and coupling devices.